Energy balance methodology and modeling of supplementary forage production for cattle in Brazil

Scientia Agricola

Thiago Libório Romanelli²  Marcos Milan¹ 

[1],Universidade de São Paulo Escola Superior de Agricultura Luiz de Quiroz Programa de Pós-Graduação em Máquinas Agrícolas

关键词: environmental management;    production systems;    sustainability;    silage;    haylage;    gestão ambiental;    sistemas de produção;    sustentabilidade;    silagem;    silagem emurchecida;   

DOI  :  10.1590/S0103-90162005000100001

来源: SciELO

【 摘 要 】

Cattle is the main protein source in Brazil and cattle production depends on preserving forage in order to decrease the influence of dry periods on grass production. To minimize such problems, some new techniques have been created to increase the yield which also leads to energy demand increase. Energy balance is a vital tool to evaluate the efficiency of energy consumption in production systems. There is no standard methodology established for this determination. It is also difficult to analyze different management options because of the complexity of the production systems and the interactions among variables. Therefore the purpose of this study is to develop a methodology that supports the development of a model, using a spreadsheet, and to use it to analyze the energy balance of production systems. The model was applied to a traditional production system of maize (Zea mays L.) silage and a Bermuda grass (Cynodon spp.) haylage. The gross energy balance presented was 14.1 energy units of output per energy units of input for maize silage and 0.98 for haylage. For the digestible energy balance, the values were 9.1 and 0.99, respectively. The total energy demanded was 74.3% in maize silage fertilizations and 99.7% in haylage irrigation. Yield and dry matter contents were indicated in a sensitivity analysis as the main critical variables for maize, whereas for haylage, it was not possible to indicate any. The best alternative scenarios for improving energy efficiency in maize silage and haylage production were the reductions of fertilizer concentration and irrigation use, respectively.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License